Hello
This post is very similar to earlier unanswered post (http://e2e.ti.com/support/arm/sitara_arm/f/791/t/365682
I attempted to modify the device tree using the BB-VIEW-LCD7-01-00A0.dts overlay which was written by Texas Instruments as a starting point there is a few items I'm missing from the lcdc at the main SDK lcdc page, that I require some more insight too. These are around the panel-info as shown below:
panel-info {
ac-bias = <255>;
ac-bias-intrpt = <0>;
dma-burst-sz = <16>;
bpp = <32>;
fdd = <0x80>;
tft-alt-mode = <0>;
stn-565-mode = <0>;
mono-8bit-mode = <0>;
sync-edge = <0>;
sync-ctrl = <1>;
raster-order = <0>;
fifo-th = <0>;
};
Is there a explanation on what the various items are like 'bpp' and 'fdd' for example?
My second question is around the frequency clock operation, while the default displays seems to use h and v sync the display I'm using only requires the a 24bit RGB888 format ,120Hz refresh, if that's the case to achieve a working display would clock frequency just need to be set at 56MHz to get the 120Hz refresh or am I missing some information.
The following example code for this is below:
display-timings {
native-mode = <&timing0>;
/* Settings for H294HM Display: */
timing0: 800x480 {
clock-frequency = <56000000>;
hactive = <800>; /*Horizontal valid data width */ /*Not required for H294HM Display */
vactive = <480>; /*Vertical valid data width */ /*Not required for H294HM Display */
hfront-porch = <40>; /*HSYNC Front Porch */ /*Not required for H294HM Display */
hback-porch = <40>; /*HSYNC Back Porch */ /*Not required for H294HM Display */
hsync-len = <48>; /*HSYNC Pulse Width */ /*Not required for H294HM Display */
vback-porch = <30>; /*VSYNC Back Porch */ /*Not required for H294HM Display */
vfront-porch = <13>; /*HSYNC Front Porch */ /*Not required for H294HM Display */
vsync-len = <3>; /*VSYNC Pulse Width */ /*Not required for H294HM Display */
hsync-active = <0>;
vsync-active = <0>;
};
To help with any question I have included the timings table of my display below:
